JOAO BATISTA BORGES SOBRINHO DORINI
Projetos de Pesquisa
Unidades Organizacionais
LIM/09 - Laboratório de Pneumologia, Hospital das Clínicas, Faculdade de Medicina
7 resultados
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- Electrical impedance tomography in acute respiratory distress syndrome(2018) BACHMANN, M. Consuelo; MORAIS, Caio; BUGEDO, Guillermo; BRUHN, Alejandro; MORALES, Arturo; BORGES, Joao B.; COSTA, Eduardo; RETAMAL, JaimeAcute respiratory distress syndrome (ARDS) is a clinical entity that acutely affects the lung parenchyma, and is characterized by diffuse alveolar damage and increased pulmonary vascular permeability. Currently, computed tomography (CT) is commonly used for classifying and prognosticating ARDS. However, performing this examination in critically ill patients is complex, due to the need to transfer these patients to the CT room. Fortunately, new technologies have been developed that allow the monitoring of patients at the bedside. Electrical impedance tomography (EIT) is a monitoring tool that allows one to evaluate at the bedside the distribution of pulmonary ventilation continuously, in real time, and which has proven to be useful in optimizing mechanical ventilation parameters in critically ill patients. Several clinical applications of EIT have been developed during the last years and the technique has been generating increasing interest among researchers. However, among clinicians, there is still a lack of knowledge regarding the technical principles of EIT and potential applications in ARDS patients. The aim of this review is to present the characteristics, technical concepts, and clinical applications of EIT, which may allow better monitoring of lung function during ARDS.
- Does Regional Lung Strain Correlate With Regional Inflammation in Acute Respiratory Distress Syndrome During Nonprotective Ventilation? An Experimental Porcine Study(2018) RETAMAL, Jaime; HURTADO, Daniel; VILLARROEL, Nicolas; BRUHN, Alejandro; BUGEDO, Guillermo; AMATO, Marcelo Britto Passos; COSTA, Eduardo Leite Vieira; HEDENSTIERNA, Goeran; LARSSON, Anders; BORGES, Joao BatistaObjective: It is known that ventilator-induced lung injury causes increased pulmonary inflammation. It has been suggested that one of the underlying mechanisms may be strain. The aim of this study was to investigate whether lung regional strain correlates with regional inflammation in a porcine model of acute respiratory distress syndrome. Design: Retrospective analysis of CT images and positron emission tomography images using [F-18]fluoro-2-deoxy-D-glucose. Setting: University animal research laboratory. Subjects: Seven piglets subjected to experimental acute respiratory distress syndrome and five ventilated controls. Interventions: Acute respiratory distress syndrome was induced by repeated lung lavages, followed by 210 minutes of injurious mechanical ventilation using low positive end-expiratory pressures (mean, 4cm H2O) and high inspiratory pressures (mean plateau pressure, 45cm H2O). All animals were subsequently studied with CT scans acquired at end-expiration and end-inspiration, to obtain maps of volumetric strain (inspiratory volume - expiratory volume)/expiratory volume, and dynamic positron emission tomography imaging. Strain maps and positron emission tomography images were divided into 10 isogravitational horizontal regions-of-interest, from which spatial correlation was calculated for each animal. Measurements and Main Results: The acute respiratory distress syndrome model resulted in a decrease in respiratory system compliance (20.33.4 to 14.0 +/- 4.9mL/cm H2O; p < 0.05) and oxygenation (Pao(2)/Fio(2), 489 +/- 80 to 92 +/- 59; p < 0.05), whereas the control animals did not exhibit changes. In the acute respiratory distress syndrome group, strain maps showed a heterogeneous distribution with a greater concentration in the intermediate gravitational regions, which was similar to the distribution of [F-18]fluoro-2-deoxy-D-glucose uptake observed in the positron emission tomography images, resulting in a positive spatial correlation between both variables (median R-2 = 0.71 [0.02-0.84]; p < 0.05 in five of seven animals), which was not observed in the control animals. Conclusion: In this porcine acute respiratory distress syndrome model, regional lung strain was spatially correlated with regional inflammation, supporting that strain is a relevant and prominent determinant of ventilator-induced lung injury.
- Bedside estimation of recruitable alveolar collapse and hyperdistension by electrical impedance tomography(2012) COSTA, E. L. V.; BORGES, J. B.; MELO, A.; SUAREZ-SIPMANN, F.; TOUFEN, C. Jr.; BOHM, S. H.; AMATO, M. B. P.Objective: To present a novel algorithm for estimating recruitable alveolar collapse and hyperdistension based on electrical impedance tomography (EIT) during a decremental positive end-expiratory pressure (PEEP) titration. Design: Technical note with illustrative case reports. Setting: Respiratory intensive care unit. Patient: Patients with acute respiratory distress syndrome. Interventions: Lung recruitment and PEEP titration maneuver. Measurements and results: Simultaneous acquisition of EIT and X-ray computerized tomography (CT) data. We found good agreement (in terms of amount and spatial location) between the collapse estimated by EIT and CT for all levels of PEEP. The optimal PEEP values detected by EIT for patients 1 and 2 (keeping lung collapse \10%) were 19 and 17 cmH2O, respectively. Although pointing to the same non1dependent lung regions, EIT estimates of hyperdistension represent the functional deterioration of lung units, instead of their anatomical changes, and could not be compared directly with static CT estimates for hyperinflation. Conclusions: We described an EIT-based method for estimating recruitable alveolar collapse at the bedside, pointing out its regional distribution. Additionally, we proposed a measure of lung hyperdistension based on regional lung mechanics. © Springer-Verlag Berlin Heidelberg 2006, 2009, 2012.
- There is no cephalocaudal gradient of computed tomography densities or lung behavior in supine patients with acute respiratory distress syndrome(2016) EL-DASH, S. A.; BORGES, J. B.; COSTA, E. L. V.; TUCCI, M. R.; RANZANI, O. T.; CARAMEZ, M. P.; CARVALHO, C. R. R.; AMATO, M. B. P.Background: There is debate whether pressure transmission within the lungs and alveolar collapse follow a hydrostatic pattern or the compression exerted by the weight of the heart and the diaphragm causes collapse localized in the areas adjacent to these structures. The second hypothesis proposes the existence of a cephalocaudal gradient in alveolar collapse. We aimed to define whether or not lung density and collapse follow a 'liquid-like' pattern with homogeneous isogravitational layers along the cephalocaudal axis in acute respiratory distress syndrome lungs. Methods: Acute respiratory distress syndrome patients were submitted to full lung computed tomography scans at positive end-expiratory pressure (PEEP) zero (before) and 25 cmH(2)O after a maximum-recruitment maneuver. PEEP was then decreased by 2 cmH2O every 4 min, and a semi-complete scan performed at the end of each PEEP step. Results: Lung densities were homogeneous within each lung layer. Lung density increased along the ventrodorsal axis toward the dorsal region (beta = 0.49, P < 0.001), while there was no increase, but rather a slight decrease, toward the diaphragm along the cephalocaudal axis and toward the heart. Higher PEEP attenuated density gradients. At PEEP 18 cmH2O, dependent lung regions started to collapse massively, while best compliance was only reached at a lower PEEP. Conclusions: We could not detect cephalocaudal gradients in lung densities or in alveolar collapse. Likely, external pressures applied on the lung by the chest wall, organs, and effusions are transmitted throughout the lung in a hydrostatic pattern with homogeneous consequences at each isogravitational layer. A single cross-sectional image of the lung could fully represent the heterogeneous mechanical properties of dependent and non-dependent lung regions.
- Comment on Borges et al. ""Regional lung perfusion estimated by electrical impedance tomography in a piglet model of lung collapse"" Reply(2012) BORGES, Joao Batista; SUAREZ-SIPMANN, Fernando; COSTA, Eduardo L. V.; HEDENSTIERNA, Goran; AMATO, Marcelo
- Regional lung perfusion estimated by electrical impedance tomography in a piglet model of lung collapse(2012) BORGES, Joao Batista; SUAREZ-SIPMANN, Fernando; BOHM, Stephan H.; TUSMAN, Gerardo; MELO, Alexandre; MARIPUU, Enn; SANDSTROM, Mattias; PARK, Marcelo; COSTA, Eduardo L. V.; HEDENSTIERNA, Goran; AMATO, MarceloBorges JB, Suarez-Sipmann F, Bohm SH, Tusman G, Melo A, Maripuu E, Sandstrom M, Park M, Costa EL, Hedenstierna G, Amato M. Regional lung perfusion estimated by electrical impedance tomography in a piglet model of lung collapse. J Appl Physiol 112: 225-236, 2012. First published September 29, 2011; doi: 10.1152/japplphysiol.01090.2010.-The assessment of the regional match between alveolar ventilation and perfusion in critically ill patients requires simultaneous measurements of both parameters. Ideally, assessment of lung perfusion should be performed in real-time with an imaging technology that provides, through fast acquisition of sequential images, information about the regional dynamics or regional kinetics of an appropriate tracer. We present a novel electrical impedance tomography (EIT)-based method that quantitatively estimates regional lung perfusion based on first-pass kinetics of a bolus of hypertonic saline contrast. Pulmonary blood flow was measured in six piglets during control and unilateral or bilateral lung collapse conditions. The first-pass kinetics method showed good agreement with the estimates obtained by single-photon-emission computerized tomography (SPECT). The mean difference (SPECT minus EIT) between fractional blood flow to lung areas suffering atelectasis was -0.6%, with a SD of 2.9%. This method outperformed the estimates of lung perfusion based on impedance pulsatility. In conclusion, we describe a novel method based on EIT for estimating regional lung perfusion at the bedside. In both healthy and injured lung conditions, the distribution of pulmonary blood flow as assessed by EIT agreed well with the one obtained by SPECT. The method proposed in this study has the potential to contribute to a better understanding of the behavior of regional perfusion under different lung and therapeutic conditions.
- Lung Inflammation Persists After 27 Hours of Protective Acute Respiratory Distress Syndrome Network Strategy and Is Concentrated in the Nondependent Lung(2015) BORGES, Joao Batista; COSTA, Eduardo L. V.; BERGQUIST, Maria; LUCCHETTA, Luca; WIDSTROM, Charles; MARIPUU, Enn; SUAREZ-SIPMANN, Fernando; LARSSON, Anders; AMATO, Marcelo B. P.; HEDENSTIERNA, GoranObjective: PET with [F-18]fluoro-2-deoxy-D-glucose can be used to image cellular metabolism, which during lung inflammation mainly reflects neutrophil activity, allowing the study of regional lung inflammation in vivo. We aimed at studying the location and evolution of inflammation by PET imaging, relating it to morphology (CT), during the first 27 hours of application of protective-ventilation strategy as suggested by the Acute Respiratory Distress Syndrome Network, in a porcine experimental model of acute respiratory distress syndrome. Design: Prospective laboratory investigation. Setting: University animal research laboratory. Subjects: Ten piglets submitted to an experimental model of acute respiratory distress syndrome. Interventions: Lung injury was induced by lung lavages and 210 minutes of injurious mechanical ventilation using low positive end-expiratory pressure and high inspiratory pressures. During 27 hours of controlled mechanical ventilation according to Acute Respiratory Distress Syndrome Network strategy, the animals were studied with dynamic PET imaging of [F-18]fluoro-2-deoxy-D-glucose at two occasions with 24-hour interval between them. Measurements and Main Results: [F-18]fluoro-2-deoxy-D-glucose uptake rate was computed for the total lung, four horizontal regions from top to bottom (nondependent to dependent regions) and for voxels grouped by similar density using standard Hounsfield units classification. The global lung uptake was elevated at 3 and 27 hours, suggesting persisting inflammation. In both PET acquisitions, nondependent regions presented the highest uptake (p = 0.002 and p = 0.006). Furthermore, from 3 to 27 hours, there was a change in the distribution of regional uptake (p = 0.003), with more pronounced concentration of inflammation in nondependent regions. Additionally, the poorly aerated tissue presented the largest uptake concentration after 27 hours. Conclusions: Protective Acute Respiratory Distress Syndrome Network strategy did not attenuate global pulmonary inflammation during the first 27 hours after severe lung insult. The strategy led to a concentration of inflammatory activity in the upper lung regions and in the poorly aerated lung regions. The present findings suggest that the poorly aerated lung tissue is an important target of the perpetuation of the inflammatory process occurring during ventilation according to the Acute Respiratory Distress Syndrome Network strategy.